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At least 361 records · Page 20Linked to original sources

USGS2002

Migration of wood-preserving chemicals in contaminated groundwater in a sand aquifer at Pensacola, Florida

Operation of a wood-preserving facility for nearly 80 years at Pensacola, FL, contaminated the near-surface groundwater with creosote and pentachlorophenol. The major source of aquifer contamination was unlined surface impoundments that were in direct hydraulic contact with the groundwater. Episodes of overtopping the impoundments and overland flow of treatment liquor and waste were also significant to the migration and contamination of the groundwater. Solutes contaminating the ground-water are mainly naphthalene and substituted phenols. Sorption did not influence retardation of solutes in transport in the groundwater. Phenol and the mono substituted methylphenols appear to be undergoing bio-transformation. Pentachlorophenol (PCP) was not found in significant concentrations in the groundwater possibly because the solubility of PCP is approximately 5 mg/L at pH 6, near the average acidity for the groundwater.

Florida↗

USGS2013

Choices in recreational water quality monitoring: new opportunities and health risk trade-offs

With the recent release of new recreational water quality monitoring criteria, there are more options for regulatory agencies seeking to protect beachgoers from waterborne pathogens. Included are methods that can reduce analytical time, providing timelier estimates of water quality, but the application of these methods has not been examined at most beaches for expectation of health risk and management decisions. In this analysis, we explore health and monitoring outcomes expected at Lake Michigan beaches using protocols for indicator bacteria including culturable Escherichia coli (E. coli; EC), culturable enterococci (ENT), and enterococci as analyzed by qPCR (QENT). Correlations between method results were generally high, except at beaches with historically high concentrations of EC. The “beach action value” was exceeded most often when using EC or ENT as the target indicator; QENT exceeded the limit far less frequently. Measured water quality between years was varied. Although methods with equivalent health expectation have been established, the lack of relationship among method outcomes and annual changes in mean indicator bacteria concentrations complicates the decision-making process. The monitoring approach selected by beach managers may be a combination of available tools that maximizes timely health protection, cost efficiency, and collaboration among beach jurisdictions.

Environmental Science & Technology↗

USGS2008

Environmental occurrence of the enterococcal surface protein ( esp ) gene is an unreliable indicator of human fecal contamination

The enterococcal surface protein ( esp ) gene found in Enterococcus faecalis and E. faecium has recently been explored as a marker of sewage pollution in recreational waters but its occurrence and distribution in environmental enterococci has not been well-documented. If the esp gene is found in environmental samples, there are potential implications for microbial source tracking applications. In the current study, a total of 452 samples (lake water, 100; stream water, 129; nearshore sand, 96; and backshore sand, 71; Cladophora sp. (Chlorophyta), 41; and periphyton (mostly Bacillariophyceae ), 15) collected from the coastal watersheds of southern Lake Michigan were selectively cultured for enterococci and then analyzed for the esp gene by PCR, targeting E. faecalis/ E. faecium ( esp fs/fm ) and E. faecium ( esp fm ). Overall relative frequencies for esp fs/fm and esp fm were 27.4 and 5.1%. Respective percent frequency for the esp fs/fm and esp fm was 36 and 14% in lake water; 38.8 and 2.3% in stream water; 24 and 6.3% in nearshore sand; 0% in backshore sand; 24.4 and 0% in Cladophora sp.; and 33.3 and 0% in periphyton. The overall occurrence of both esp fs/fm and esp fm was significantly related ( χ 2 = 49, P < 0.0001). Post-rain incidence of esp fs/fm increased in lake and stream water and nearshore sand. Further, E. coli and enterococci cell densities were significant predictors for esp fs/fm occurrence in post-rain lake water, but esp fm was not. F + coliphage densities were not significant predictors for esp fm or esp fs/fm gene incidence. In summary, the differential occurrence of the esp gene in the environment suggests that it is not limited to human fecal sources and thus may weaken its use as a reliable tool in discriminating contaminant sources (i.e., human vs nonhuman).

Environmental Science & Technology↗

USGS2011

Recent and historic drivers of landscape change in the Everglades ridge, slough, and Tree Island mosaic

More than half of the original Everglades extent formed a patterned peat mosaic of elevated ridges, lower and more open sloughs, and tree islands aligned parallel to the dominant flow direction. This ecologically important landscape structure remained in a dynamic equilibrium for millennia prior to rapid degradation over the past century in response to human manipulation of the hydrologic system. Restoration of the patterned landscape structure is one of the primary objectives of the Everglades restoration effort. Recent research has revealed that three main drivers regulated feedbacks that initiated and maintained landscape structure: the spatial and temporal distribution of surface water depths, surface and subsurface flow, and phosphorus supply. Causes of recent degradation include but are not limited to perturbations to these historically important controls; shifts in mineral and sulfate supply may have also contributed to degradation. Restoring predrainage hydrologic conditions will likely preserve remaining landscape pattern structure, provided a sufficient supply of surface water with low nutrient and low total dissolved solids content exists to maintain a rainfall-driven water chemistry. However, because of hysteresis in landscape evolution trajectories, restoration of areas with a fully degraded landscape could require additional human intervention.

Critical Reviews in Environmental Science and Tech↗

USGS2019

Chemically enhanced treatment wetland to improve water quality and mitigate land subsidence in the Sacramento-San Joaquin Delta: Cost and design considerations

Water quality impairment and land surface subsidence threaten the viability of the Sacramento-San Joaquin Delta (Delta), a critical component of California’s water conveyance system. Current day irrigation drainage through Delta island peat soils impacts drinking water treatment and is linked to mercury transport, potentially posing both ecological and public health concerns. Hybrid coagulation-treatment wetland systems, termed Chemically Enhanced Treatment Wetlands (CETWs), were studied as a means to cost-effectively treat agricultural drainage water from subsided Delta islands to reduce the export of drinking water quality constituents of concern and mitigate land subsidence through accretion. We provide cost estimates and design recommendations to aid broader implementation of this technology. Over a 20-year horizon using a Total Annualized Cost analysis, we estimate treatment costs of $602 – $747 per acre-foot (ac-ft) water treated and $36 – $70 per kg dissolved organic carbon (DOC) removed depending upon source water DOC concentrations for a small 3-acre CETW system. For larger CETW systems scaled for island sizes of 3,500 – 14,000 acres, costs decrease to $108 – $239 per ac-ft water treated and $11 – $14 per kg DOC removed. The footprints of CETW systems were estimated to be approximately 3% of the area being treated for 4-day hydraulic retention time systems but would decrease to less than 1% for 1-day hydraulic retention time systems. CETWs ultimately address several of the Delta’s key internal issues while keeping water treatment costs competitive with other currently available treatment technologies at similar scales on a per carbon removed basis. CETWs offer a reliable system to reduce out-going DOC and mercury loads and they provide the additional benefit of sediment accretion. System costs and treatment efficacy are highly dependent on inflow source water conditions, land availability and other practical matters. To keep costs low and removal efficacy high, wetland design features will need site-specific evaluation.

California↗

USGS2009

Evaluating hydrological response to forecasted land-use change—scenario testing with the automated geospatial watershed assessment (AGWA) tool

Envisioning and evaluating future scenarios has emerged as a critical component of both science and social decision-making. The ability to assess, report, map, and forecast the life support functions of ecosystems is absolutely critical to our capacity to make informed decisions to maintain the sustainable nature of our ecosystem services now and into the future. During the past two decades, important advances in the integration of remote imagery, computer processing, and spatial-analysis technologies have been used to develop landscape information that can be integrated with hydrologic models to determine long-term change and make predictive inferences about the future. Two diverse case studies in northwest Oregon (Willamette River basin) and southeastern Arizona (San Pedro River) were examined in regard to future land use scenarios relative to their impact on surface water conditions (e.g., sediment yield and surface runoff) using hydrologic models associated with the Automated Geospatial Watershed Assessment (AGWA) tool. The base reference grid for land cover was modified in both study locations to reflect stakeholder preferences 20 to 60 yrs into the future, and the consequences of landscape change were evaluated relative to the selected future scenarios. The two studies provide examples of integrating hydrologic modeling with a scenario analysis framework to evaluate plausible future forecasts and to understand the potential impact of landscape change on ecosystem services.

Conference Paper↗

USGS2015

Application of a microfluidic quantitative polymerase chain reaction technique to monitor bacterial pathogens in beach water and complex environmental matrices

Microfluidic quantitative polymerase chain reaction (MFQPCR) and conventional quantitative polymerase chain reaction methods were compared side by side in detecting and quantifying 19 genetic markers associated with Escherichia coli and select bacterial pathogens in algae, beach sand, and water from Lake Michigan. Enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli , Salmonella spp., Campylobacter jejuni , and Clostridium perfringens were among the pathogens tested. Of the pathogenic markers, eaeA that encodes intimin in EPEC was detected in all sample types: water (5%), detached/floating algae (42%), exposed/stranded algae (43%), sand below exposed algae (27%), and nearshore sand with no algae (22%). Other pathogenic markers, however, were detected sporadically. Despite comparable results from the two methods for the genetic markers tested in this study, the MFQPCR method may be superior, with the advantage of detecting and quantifying multiple pathogens simultaneously in environmental matrices.

Indiana↗

USGS2011

Mercury export from the Yukon River Basin and potential response to a changing climate

We measured mercury (Hg) concentrations and calculated export and yield from the Yukon River Basin (YRB) to quantify Hg flux from a large, permafrost-dominated, high-latitude watershed. Exports of Hg averaged 4400 kg Hg yr -1 . The average annual yield for the YRB during the study period was 5.17 μg m -2 yr -1 , which is 3–32 times more than Hg yields reported for 8 other major northern hemisphere river basins. The vast majority (90%) of Hg export is associated with particulates. Half of the annual export of Hg occurred during the spring with about 80% of 34 samples exceeding the U.S. EPA Hg standard for adverse chronic effects to biota. Dissolved and particulate organic carbon exports explained 81% and 50%, respectively, of the variance in Hg exports, and both were significantly ( p < 0.001) correlated with water discharge. Recent measurements indicate that permafrost contains a substantial reservoir of Hg. Consequently, climate warming will likely accelerate the mobilization of Hg from thawing permafrost increasing the export of organic carbon associated Hg and thus potentially exacerbating the production of bioavailable methylmercury from permafrost-dominated northern river basins.

Alaska↗

USGS1995

Fate of linear alkylbenzene sulfonate in the Mississippi River

The 2 800-km reach of the Mississippi River between Minneapolis, MN, and New Orleans, LA, was examined for the occurrence and fate of linear alkylbenzene sulfonate (LAS), a common anionic surfactant found in municipal sewage effluents. River water and bottom sediment were sampled in the summer and fall of 1991 and in the spring of 1992. LAS was analyzed using solid-phase extraction/derivatization/ gas chromatography/mass spectrometry. LAS was present on all bottom sediments at concentrations ranging from 0.01 to 20 mg/kg and was identified in 21% of the water samples at concentrations ranging from 0.1 to 28.2 μg/L. The results indicate that LAS is a ubiquitous contaminant on Mississippi River bottom sediments and that dissolved LAS is present mainly downstream from the sewage outfalls of major cities. The removal of the higher LAS homologs and external isomers indicates that sorption and biodegradation are the principal processes affecting dissolved LAS. Sorbed LAS appears to degrade slowly.

Environmental Science & Technology↗

USGS2016

Hydrologic controls on nitrogen cycling processes and functional gene abundance in sediments of a groundwater flow-through lake

The fate and transport of inorganic nitrogen (N) is a critically important issue for human and aquatic ecosystem health because discharging N-contaminated groundwater can foul drinking water and cause algal blooms. Factors controlling N-processing were examined in sediments at three sites with contrasting hydrologic regimes at a lake on Cape Cod, MA. These factors included water chemistry, seepage rates and direction of groundwater flow, and the abundance and potential rates of activity of N-cycling microbial communities. Genes coding for denitrification, anaerobic ammonium oxidation (anammox), and nitrification were identified at all sites regardless of flow direction or groundwater dissolved oxygen concentrations. Flow direction was, however, a controlling factor in the potential for N-attenuation via denitrification in the sediments. Potential rates of denitrification varied from 6 to 4500 pmol N/g/h from the inflow to the outflow side of the lake, owing to fundamental differences in the supply of labile organic matter. The results of laboratory incubations suggested that when anoxia and limiting labile organic matter prevailed, the potential existed for concomitant anammox and denitrification. Where oxic lake water was downwelling, potential rates of nitrification at shallow depths were substantial (1640 pmol N/g/h). Rates of anammox, denitrification, and nitrification may be linked to rates of organic N-mineralization, serving to increase N-mobility and transport downgradient.

Massachusetts↗

USGS2005

Arsenate adsorption mechanisms at the allophane: Water interface

We investigated arsenate (As(V)) reactivity and surface speciation on amorphous aluminosilicate mineral (synthetic allophane) surfaces using batch adsorption experiments, powder X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). The adsorption isotherm experiments indicated that As(V) uptake increased with increasing [As(V)] o from 50 to 1000 μM (i.e., Langmuir type adsorption isotherm) and that the total As adsorption slightly decreased with increasing NaCl concentrations from 0.01 to 0.1 M. Arsenate adsorption was initially (0−10 h) rapid followed by a slow continuum uptake, and the adsorption processes reached the steady state after 720 h. X-ray absorption spectroscopic analyses suggest that As(V) predominantly forms bidentate binuclear surface species on aluminum octahedral structures, and these species are stable up to 11 months. Solubility calculations and powder XRD analyses indicate no evidence of crystalline Al−As(V) precipitates in the experimental systems. Overall, macroscopic and spectroscopic evidence suggest that the As(V) adsorption mechanisms at the allophane−water interface are attributable to ligand exchange reactions between As(V) and surface-coordinated water molecules and hydroxyl and silicate ions. The research findings imply that dissolved tetrahedral oxyanions (e.g., H 2 PO 4 2 - and H 2 AsO 4 2 - ) are readily retained on amorphous aluminosilicate minerals in aquifer and soils at near neutral pH. The inner-sphere adsorption mechanisms might be important in controlling dissolved arsenate and phosphate in amorphous aluminosilicate-rich low-temperature geochemical environments.

Environmental Science & Technology↗

USGS2022

Fishway Entrance Palisade

This technical report summarizes the work that was conducted by the University of Massachusetts Amherst and the United States Geological Survey (USGS), along with other project partners, on the Fishway Entrance Palisade (EP), a projected funded through the Department of Energy’s (DOE) funding opportunity titled ‘Innovative Solutions for Fish Passage at Hydropower Dams’ (DE‐FOA‐0001662). The period of performance ranged from September 1, 2018 through September 30, 2021. The EP is a novel fish passage engineering technology designed to provide more favorable entry conditions for fish and to reduce costs relative to conventional fishway auxiliary water systems (AWS). The EP project has four primary components. First, the Northeast United States Auxiliary Water Systems Database was created (Northeast Fishway Auxiliary Water Systems Database Section). The database, developed with material provided by the U.S. Fish and Wildlife Service, contains information on fishway type (e.g., lift, Denil, pool and weir) and Auxiliary Water System (AWS) details (e.g., water conveyance method, diffuser type) for 60 hydroelectric sites in the region. Findings indicate that nearly 4 out of every 10 fishway in the region is a fish lift and approximately 1 out of every 4 is a Denil ladder. The remainder are a mix of vertical slot fishways, pool and weirs, and Ice Harbor fishways. Furthermore, over half of all AWS systems use floor diffusers to discharge the auxiliary (or attraction) water into the entrance of a fishway, whereas only 14% use wall diffusers. Second, limited experiments on a conventional AWS with live, actively migrating fish were conducted at the USGS Easter Ecological Science Center (EESC) S.O. Conte Research Laboratory (Conventional Auxiliary Water System Experiments Section). This study determined how water velocity through a wall diffuser, without turning vanes or timber baffles to distribute the flow, affects the behavior and passage of adult American shad, a conservative surrogate species for migratory fish on the East Coast. Two gross diffuser velocity treatments were examined, 0.5 ft/s and 1.0 ft/s. These wall diffuser velocities represented current (0.5 ft/s) and past (1.0 ft/s) design criteria guidelines set forth by the USFWS North Atlantic-Appalachian Region (Rojas 2020; USFWS 2019). Six trials with a total of 151 American Shad were conducted in June of 2019 for the two treatments. No differences in American shad passage efficiency were discovered between the two treatments, while approximately 3 in every 4 attempts were successful at passing the diffuser. While these results may appear to indicate that the generally accepted gross wall diffuser velocity criteria for American shad of 0.5 ft/s could be safely increased to 1.0 ft/s, further analysis is warranted. Furthermore, it is unknown how other migratory and resident fish species that traverse these structures would be impacted by such a change. Studying the wall diffuser hydraulics led to an important AWS observation. Without turning vanes or timber baffles in this study, doubling the diffuser area was insufficient at producing the type of flow field change one may expect by halving the gross diffuser velocity. Instead, the flow fields throughout each treatments study area were similar, which led to similar results in shad performance. This not only highlights the importance of installing flow guidance devices like turning vanes, but also to the importance of properly maintaining them, which can be costly. Third, more expansive experiments on the novel EP were conducted in the spring of 2019 and 2021 (Fishway Entrance Palisade Experiments). The goal of this study was to determine how adult American shad responded to a variety of conditions at a full-scale EP. A total of six treatments were examined by changing the average auxiliary channel velocity between 1.0 and 5.0 ft/s in intervals of 1.0 ft/s and by inserting/removing an entrance gate at the opening of the fishway. Thirty trials with a total of 1,273 shad were conducted over the two years. In all treatments, at least ~7 out of every 10 fish successfully passed the EP diffuser and swam into the entrance channel within the 3.5-hour long trial, highlighting the general effectiveness of the novel AWS technology. In both study years, lower velocities through the EP diffuser led to increased shad performance, though performance peaked for the 2 ft/s velocity treatment. This treatment condition represents an approximate six-fold increase in gross diffuser velocity relative to conventional auxiliary water systems, which in turn presents opportunities for cost savings (e.g., reduction in diffuser size). Shad performance, in general, was worse in 2019 than in 2021, potentially due to the different run timing when our trials were conducted (2019 trials occurred near the end of the migration season, unlike in 2021). Treatments in 2019 had approximately a 20% reduction in entrance efficiency by the trial end, including a 16.7% drop for the 3 ft/s velocity treatment in 2019 relative to 2021 (the only carryover treatment between years). Lastly, adding an entrance gate caused a significant delay to entry. The time to 25% entry raised ~20 minutes from the near instantaneous 25% entry that was reported for the other treatments conducted in the same year (2021). Though by the end of the 3.5-hour trial, the overall entrance efficiency nearly matched those of the other 2021 treatments. The fourth and final component of the EP project was an economic analysis that focused on the cost of attraction and environmental flows (Modeling Power Generation Losses Due to Environmental and Fish Passage Attraction Flows at a Run-Of-River Hydroelectric Operation in the Northeast). The study assessed the economic impact of meeting environmental flow requirements at a representative hydroelectric facility and fish lift in the Northeast. An initial finding of the study was that there is a paucity of published data on the costs of meeting attraction and environmental flows. This is due, in part, to the proprietary nature of this data. To explore the costs associated with these flows, three types of environmental flows were assessed: upstream fishway attraction flows, downstream fishway attraction flows, and habitat maintenance minimum flows. A physics-based model was developed and calibrated with three years of hourly generation and flow data as inputs. Gage flow inputs were adjusted and used to calculate power generated. To address hydrologic variability, the model was executed to simulate 30 years of historical flows. Results indicate that both interannual and seasonal climatic factors impact the costs of meeting environmental flow requirements. Generation potential is most strongly curtailed during dry years in terms of maximizing the capacity factor (the percent of time a plant generates at capacity). Dry years, and especially dry summers, have the most significant costs associated with mitigation flows. Of the three types of flows, habitat flows are most costly in terms of power production, followed by upstream attraction flows. Downstream attraction flows are least costly. This finding is the likely result of differences in both flow rates and duration of the seasonal requirement for each flow. Overall, environmental flows represented a 2-12% loss in annual generation, but losses during a dry summer can reach over 20%.

Final Technical Report↗

USGS2019

Long-term annual aerial surveys of submersed aquatic vegetation (SAV) support science, management, and restoration

Aerial surveys of coastal habitats can uniquely inform the science and management of shallow, coastal zones, and when repeated annually, they reveal changes that are otherwise difficult to assess from ground-based surveys. This paper reviews the utility of a long-term (1984-present) annual aerial monitoring program for submersed aquatic vegetation (SAV) in Chesapeake Bay, its tidal tributaries, and nearby Atlantic coastal bays, USA. We present a series of applications that highlight the program’s importance in assessing anthropogenic impacts, gauging water quality status and trends, establishing and evaluating restoration goals, and understanding the impact of commercial fishing practices on benthic habitats. These examples demonstrate how periodically quantifying coverage of this important foundational habitat answers basic research questions locally as well as globally, and provides essential information to resource managers. New technologies are enabling more frequent and accurate aerial surveys at greater spatial resolution and lower cost. These advances will support efforts to extend the applications described here to similar issues in other areas

Chesapeake Bay↗

USGS2017

Vertical datum conversion process for the inland and coastal gage network located in the New England, Mid-Atlantic, and South Atlantic-Gulf hydrologic regions

Datum conversions from the National Geodetic Vertical Datum of 1929 to the North American Vertical Datum of 1988 among inland and coastal gages throughout the hydrologic regions of New England, the Mid-Atlantic, and the South Atlantic-Gulf have implications among river and storm surge forecasting, general commerce, and water-control operations. The process of data conversions may involve the application of a recovered National Geodetic Vertical Datum of 1929–North American Vertical Datum of 1988 offset, a simplistic datum transformation using VDatum or VERTCON software, or a survey, depending on a gaging network datum evaluation, anticipated uncertainties for data use among the cooperative water community, and methods used to derive the conversion. Datum transformations from National Geodetic Vertical Datum of 1929 to North American Vertical Datum of 1988 using VERTCON purport errors of ± 0.13 foot at the 95 percent confidence level among modeled points, claiming more consistency along the east coast. Survey methods involving differential and trigonometric leveling, along with observations using Global Navigation Satellite System technology, afford a variety of approaches to establish or perpetuate a datum during a survey. Uncertainties among leveling approaches are generally < 0.1 foot, and and Global Navigation Satellite System approaches may be categorized with uncertainties of ≤0.1 foot for a Level I quality category and ≥0.1 foot for Level II or III quality categories (defined by the U.S. Geological Survey) by observation and review of experienced practice. The conversion process is initiated with an evaluation of the inland and coastal gage network datum, beginning with altitude datum components and the history of those components queried through the U.S. Geological Survey Groundwater Site Inventory database. Subsequent edits to the Groundwater Site Inventory database may be required and a consensus reached among the U.S. Geological Survey Water Science Centers to identify the outstanding workload categorized as in-office datum transformations or offset applications versus out-of-office survey efforts. Datum conversions or datum establishment for the inland or coastal gaging network should meet datum uncertainty requirements among other Federal agencies. Datum uncertainty requirements are ±0.25 foot for U.S. Army Corps of Engineers water-control or construction projects and ±0.16 foot for Federal Emergency Management Agency field surveys and checkpoint surveys used for mapping. River level forecasts generally are defined as ± 0.10 foot among the National Oceanic and Atmospheric Administration–National Weather Service. Collaboration and communication among the cooperative water community is necessary during a datum conversion or datum change. Datum notification time-change requirements set by the National Oceanic and Atmospheric Administration–National Weather Service vary from 30 to 120 days, depending on datum conversion or datum-change case scenarios. Notification times associated with these case scenarios may be useful to the National Oceanic and Atmospheric Administration–National Weather Service and U.S. Army Corps of Engineers, because their daily operations are time sensitive, unlike the notification time change requirements of other entities that make up the cooperative water community. At the time of this writing, a future geopotential datum resulting from Gravity for the Redefinition of the American Vertical Datum is anticipated in 2022. A future version of VDatum and VERTCON is anticipated to provide a transformation among North American Vertical Datum of 1988 elevations to the new geopotential datum.

Techniques and Methods↗

USGS2023

Editorial: Advanced physico-chemical technologies for water detoxification and disinfection

One of the most critical challenges we face today is access to clean water. Climate change, industrialization, high rates of urbanization, and population growth have resulted in many countries suffering from water crises, especially in the arid and semi-arid areas. Countries in different regions of the world have also been struggling over regional water availability and it is anticipated that these struggles may result in conflicts over shared water resources in these regions. Considering the adverse consequences of the water crisis, countries have been trying to increasingly cope with this problem of water availability by implementing sustainable water management plans and looking for alternative water supply sources.

Frontiers in Environmental Science↗

USGS2026

Colocating artificial intelligence data centers with energy infrastructure on Federal public lands—A science synthesis and spatial analysis to inform decision making

Executive Summary Artificial intelligence (AI) is rapidly transforming industries and economies, creating an urgent need to strategically plan for the energy and infrastructure required to support increasing AI use. U.S. Federal agencies and bureaus have been directed to explore ways to accelerate permitting, development, and deployment of energy resources and AI technologies, including encouraging the colocation of energy infrastructure and data centers. To inform these initiatives, this report synthesizes relevant scientific information and presents a spatial analysis of existing energy infrastructure and data centers on or near U.S. Federal public lands managed by the Bureau of Land Management (BLM). The purpose of this science synthesis and spatial analysis is to provide the BLM with foundational information for considering potential colocation of data centers with energy infrastructure on Federal public lands to support evidence-based decisions. Additionally, this report provides insight into current (2025) and potential future energy demands by providing projections of a range of potential future environmental conditions relevant to maintaining industry-recommended cooling temperature standards necessary for efficient data center operations. As a part of this effort, a rapid response literature review was conducted of the best available science on the topic of data center development and energy infrastructure in July–August 2025, supplemented by additional resources recommended by U.S. Federal agency and bureau subject matter experts (hereafter experts; including the U.S. Department of Energy National Laboratory of the Rockies) and peer reviewers. To better understand current conditions relevant to AI data center development, a spatial analysis was conducted across Alaska and 11 States in the Western United States, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming, all of which contain extensive BLM-managed surface lands (hereafter referred to as “BLM lands”) that could be considered for the colocation of energy infrastructure and AI data centers. This effort identified BLM lands within 10 miles of existing transmission lines, consistent with methods used in previous BLM programmatic environmental impact statements. This report describes the types of data centers operating within the United States, which vary in ownership, size, technology, and proximity to end users. This report then outlines the primary considerations of data center development, including reliable energy supply, natural resources (such as water availability to support cooling requirements), and relevant policy and regulatory considerations. Energy supply considerations are pivotal for data center operation. Between 2014 and 2018, data centers in the United States accounted for nearly 2 percent of the Nation’s total electricity consumption, and data center energy consumption is projected to increase from 2 to 6.7–12 percent of total U.S. electricity use by 2028. These energy requirements necessitate careful consideration of energy supply when considering potentially suitable locations for data center development. Experts anticipate that an increase in renewable energy generation will likely support most potential future power demand needs, including for data centers, followed by increases in natural gas, nuclear, and geothermal energy production. Additional capacity in the form of battery storage will likely not generate electricity, but may improve the reliability and flexibility of supply, helping to ensure that growing data center loads can be met. However, the U.S. Department of Energy estimates that the United States will need, on average, 57 percent more energy transmission infrastructure by 2035 to account for the growing power demand introduced by development such as data centers. Cooling server equipment in data centers requires large amounts of electricity and water, and this demand can be exacerbated by hot and humid conditions. Energy efficient water-based cooling technologies may reduce electricity consumption onsite but require more water consumption. This additional water demand has the potential to increase water stress and competition with other users. As such, developing data centers will likely need a thorough assessment of current and potential future water availability, as well as consideration of how water demand may change across other sectors. Data center development involves policy and regulatory considerations, as projects must undergo environmental review and authorization processes that can take 18–24 months. Coordinating these environmental reviews and authorizations with other energy development projects, such as building new transmission lines, may cause additional delays. Recent efforts by the U.S. Department of Energy and U.S. Department of the Interior aim to expedite environmental reviews and authorizations and improve coordination across agencies. The spatial analysis identified 771 existing AI data centers and more than 3,300 power plants. The spatial analysis found that 6 percent of AI data centers and 22 percent of power plants in the Western United States were on or within 1 mile of BLM lands, and California had the largest number of facilities. Most existing AI data centers were near high-voltage transmission lines and close to power plants, supporting efficient energy delivery. More than 90,000,000 acres of BLM lands were within 10 miles of existing high-voltage transmission lines, representing 38 percent of BLM lands in the study area. Available transmission infrastructure and the overlap with BLM lands varied by State, and Alaska had limited overlap compared to the rest of the Western United States. To operate most efficiently, data center temperatures must be at or below 80.6 degrees Fahrenheit. This analysis of future temperature and precipitation projections indicated increasing cooling demands for data centers, particularly in Arizona, California, and Nevada, where rising temperatures are expected to increase energy and operational costs while potentially stressing current regional electrical grid infrastructure. This report highlights relevant energy supply, natural resources, and regulatory considerations for data center development on BLM lands. This report does not provide a comprehensive ecological, regulatory, land suitability, or permitting analysis. The factors described here are contextual considerations only and are not intended to identify, rank, quantify, or recommend optimal areas for data center colocation. This spatial analysis focused solely on energy considerations relevant to data centers and did not consider water availability, critical habitats, BLM National Conservation Lands, areas of cultural or historical significance, and other sensitive resources. These topics are recognized as critical but were not within the scope of this science synthesis and spatial analysis.

Scientific Investigations Report↗

USGS2024

Characterizing the areal extent of PFAS contamination in fish species downgradient of AFFF source zones

Most monitoring programs next to large per- and polyfluoroalkyl substances (PFAS) sources focus on drinking water contamination near source zones. However, less is understood about how these sources affect downgradient hydrological systems and food webs. Here, we report paired PFAS measurements in water, sediment, and aquatic biota along a hydrological gradient away from source zones contaminated by the use of legacy aqueous film-forming foam (AFFF) manufactured using electrochemical fluorination. Clustering analysis indicates that the PFAS composition characteristic of AFFF is detectable in water and fishes >8 km from the source. Concentrations of 38 targeted PFAS and extractable organofluorine (EOF) decreased in fishes downgradient of the AFFF-contaminated source zones. However, PFAS concentrations remained above consumption limits at all locations within the affected watershed. Perfluoroalkyl sulfonamide precursors accounted for approximately half of targeted PFAS in fish tissues, which explain >90% of EOF across all sampling locations. Suspect screening analyses revealed the presence of a polyfluoroketone pharmaceutical in fish species, and a fluorinated agrochemical in water that likely does not accumulate in biological tissues, suggesting the presence of diffuse sources such as septic system and agrochemical inputs throughout the watershed in addition to AFFF contamination. Based on these results, monitoring programs that consider all hydrologically connected regions within watersheds affected by large PFAS sources would help ensure public health protection.

Massachusetts↗

USGS2017

Spatial dependence of reduced sulfur in Everglades dissolved organic matter controlled by sulfate enrichment

Sulfate inputs to the Florida Everglades stimulate sulfidic conditions in freshwater wetland sediments that affect ecological and biogeochemical processes. An unexplored implication of sulfate enrichment is alteration of the content and speciation of sulfur in dissolved organic matter (DOM), which influences the reactivity of DOM with trace metals. Here, we describe the vertical and lateral spatial dependence of sulfur chemistry in the hydrophobic organic acid fraction of DOM from unimpacted and sulfate-impacted Everglades wetlands using X-ray absorption spectroscopy and ultrahigh-resolution mass spectrometry. Spatial variation in DOM sulfur content and speciation reflects the degree of sulfate enrichment and resulting sulfide concentrations in sediment pore waters. Sulfur is incorporated into DOM predominantly as highly reduced species in sulfidic pore waters. Sulfur-enriched DOM in sediment pore waters exchanges with overlying surface waters and the sulfur likely undergoes oxidative transformations in the water column. Across all wetland sites and depths, the total sulfur content of DOM correlated with the relative abundance of highly reduced sulfur functionality. The results identify sulfate input as a primary determinant on DOM sulfur chemistry to be considered in the context of wetland restoration and sulfur and trace metal cycling.

Florida↗